LOINC

LOINC Code 4648-2: Homologous restriction factor

4648-2 is a LOINC code used to identify Homologous restriction factor in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Homologous restriction factor. It is commonly used with the system or sample type -.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Homologous restriction factor. It is commonly used with the system or sample type -.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: DEPRECATED

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • Deprecated Homologous restriction factor
  • Homologous restriction factor
  • Fac; Fact; HEMATOLOGY/CELL COUNTS; Point in time; Random

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Homologous restriction factorDeprecated Homologous restriction factorHEM/BC-PtPoint in time (spot)

Frequently asked questions

Code details

Code4648-2
SystemLOINC
Display nameHomologous restriction factor
Short nameDeprecated Homologous restriction factor
ComponentHomologous restriction factor
Property-
TimingPt
System (specimen)-
Scale-
ClassHEM/BC
StatusDEPRECATED

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.66

Consumer names

Homologous Restriction Factor

Part names

Homologous restriction factor-PtPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 4648-2 | HealthAssure